Andreaea Hedw., Sp. Musc. Frond. 47. 1801.
The description of the genus is the same as that of the family.
The presence of thalloid protonemata and pseudopodium as well as the dehiscence of capsules by vertical splits are distinguishing features of Andreaea. The genus is worldwide in distribution, but it has not been revised as a whole. Murray (1988) estimated that there were fewer than fifty species in the world. In China there are four species and one subspecies of Andreaea. All Chinese taxa belong to the ecostate group (section Andreaea). In the recent Chinese moss checklist (Redfearn et al. 1996), Andreaea amurensis Broth. was reported from Changbai Shan, Jilin province, based on a reference of C. Gao and K.-C. Chang (1983), and Andreaea sinuosa Murray was recorded from Taiwan based on a thesis (T.-Y. Chiang 1989). In a revision of Chinese Andreaea, T. Cao and C. Gao (1995) did not mention the report of Andreaea amurensis from Jilin, nor did they verify A. sinuosa from Taiwan. According to Murray (1986), Andreaea sinuosa is a very rare species known only from localities in Alaska, British Columbia, and Scotland. Most recently in a taxonomic revision of Andreaea in Taiwan, T.-Y. Chiang (1998) described a new species, A. taiwanensis, and clarified that A. sinuosa from Taiwan was misidentified from a specimen of A. wangiana. The new species is closely related to A. mutabilis, and the major difference between the two species is the narrowly rectangular to linear median laminal cells of A. taiwanensis (T.-Y. Chiang 1998). Since we have not seen the type, we did not include this new species from Taiwan in the key.
1. Andreaea kashyapii Dix. ex Vohra & Wadhwa, Bull. Bot. Surv. India 6: 321. 1964. Type. China: Tibet, S. R. Kashyap s.n. (holotype BM).
This species is a taxonomic synonym of Didymodon subandreaeoides (Kindb.) Zander (T. Cao & C. Gao 1995: 22).
2. Andreaea yunnanensis Broth., Symb. Sin. 4: 9. 1929. Type. China: Yunnan, Handel-Mazzetti 6952 (holotype H).
This species is a taxonomic synonym of Didymodon nigrescens (Mitt.) Saito (T. Cao & C. Gao 1995: 19, Fig. 7, A–J).